In 2012, Jackson moved to the AAA Memphis Redbirds and in anticipation of getting called up to the majors, began to receive some playing time at second base in addition to short. he continued to hit well for a middle infielder, with a batting line of .272/.334/.396, with 23 doubles and 10 homers in 117 games. He got the call to the major sin early August but only went 2 for 17 in 13 games. With starting SS Rafael Furcal injured down the stretch, the Cardinals had to make a choice as to who would replace him in the postseason but decided on Ryan's Memphis teammate Pete Kozma, who had only hit .232 while splitting time between second base and short, judging he had a better glove. Thus Kozma was part of a World Series-winning team, while Jackson stayed on the sidelines . He returned for another full season at Memphis in 2013 as Kozma got the starting job in St. Louis with Furcal out for the year. Jackson hit his customary .278, adding 19 doubles but only 3 homers. he got playing time at third base and in the outfield in addition to shortstop and second, but even though Kozma hit a weak .217 in the Gateway City, Jackson hardly saw any big league action, going 0 for 7 in 7 games and being off the postseason roster once again.